Emerging food-borne parasites

Risk factors of foodborne parasitic diseases still remain in China: a WeChat-based knowledge, attitudes, and practices study

OBJECTIVE

With the progress of economic globalization and food diversification, foodborne parasitic diseases pose a significant public health challenge in China. This study aimed to explore the knowledge, attitudes, and practices regarding foodborne parasitic diseases among the Chinese population via WeChat, which is a promising tool for disease surveillance and health education.

METHODS

Using a questionnaire, this cross-sectional study was conducted on September 25, 2023. Participants completed a structured questionnaire by scanning a QR code provided in a tweet from the WeChat official account of the Jiangsu Institute of Parasite Disease. Multivariable logistic regression analysis was employed to explore potential independent determinants of adequate knowledge of foodborne parasitic diseases, and the positive attitude and good practice rates of the participants were calculated.

RESULTS

In total, 5,675 valid questionnaires were collected via the WeChat official account. Most participants (79.91%) fell within the age range of 20-40 years, with a higher representation of males (53.18%), and 89.80% were of Han Chinese ethnicity. It was found that 76.65% of the participants had adequate level of knowledge. Multivariable logistic regression analysis revealed that individuals of Hui nationality (OR = 0.57, 95% CI: 0.40-0.81, p = 0.002), clinicians (OR = 0.13, 95% CI: 0.09-0.19, p < 0.001), teachers (OR = 0.48, 95% CI: 0.34-0.69, p < 0.001), and government staff (OR = 0.40, 95% CI: 0.30-0.53, p < 0.001) had significantly higher levels of knowledge. Among the participants, 33.9% reported consuming raw fish or drunken shrimp, 10.6% would still try to consume raw fish despite the risk of parasitic infection, and 84.1% did not use separate cutting boards for raw and cooked foods in their kitchens.

CONCLUSIONS

Although majority of the Chinese public (76.65%) demonstrates adequate level of knowledge on foodborne parasitic diseases, there is a need to enhance personal hygiene practices and dietary habits, particularly the utilization of distinct cutting boards and the consumption of raw fish. A WeChat official account is an accessible tool for spreading foodborne parasitic diseases related health information to the public. WeChat-based health education should be implemented to enhance public awareness regarding the prevention and control of foodborne parasitic diseases.

Is it possible to eliminate or eradicate human fish-borne parasitic diseases? A sweet dream or a nightmare?

Human fish-borne parasitic diseases may be caused by at least 111 taxa of both freshwater and marine fish parasites. It is estimated that they occur in many hundreds of millions of people all over the world, and many more are at risk, sometimes with serious consequences including the death of the host. Therefore, all efforts must be made to minimize and prevent the infection. In this paper we present an overview detailing the several types of parasites infecting humans, the reasons for the occurrence of the disease, the ways of infection, the preventive measures and difficulties encountered when combating such infections. Finally, we discuss the possibility of eliminating or eradicating fish-borne diseases. It is concluded that elimination is difficult to achieve but it is possible in some places under favourable circumstances, and that eradication will probably never be fully achieved.

Allergenic response induced by Pterobothrium crassicolle (Cestoda: Trypanorhyncha) extracts in murine model

The aim of this study was to determine the allergenic activity of components present in crude extracts of Pterobothrium crassicolle plerocerci (CPE) and blastocysts (CBE) obtained from Micropogonias furnieri in a murine model. Two groups of seven animals each received 50 µg of CPE or CBE on days 1, 35 and 120. Serum samples were tested by ELISA and Immunoblotting. Specific IgG and IgE levels were detected by ELISA, showing specific humoral responses for the primary immunization for both immunoglobulins and continuously growing titers for IgE. Positive Passive Cutaneous Anaphylaxis tests in rats sensitized with anti-CBE sera and tested by CBE, showed biologically, the allergenic activity of the extracts. The CPE and CBE showed some different recognition regions but both experimental groups recognized all regions of the extracts when tested for cross reactions, showing that CPE and CBE could share antigenic recognition sites.

Examining the molecular epidemiology of Giardia and Eimeria species in Japan: a comprehensive review

Globally, animals and humans suffer from diarrheal illnesses due to protozoan parasites such as Giardia and Eimeria species. The molecular epidemiology of these parasites in Japan is summarized in this review. In humans, researchers found only one main species of Giardia, which is most referred to as G. lamblia, but it's also known by different names like G. duodenalis or G. intestinalis. However, within this species, six assemblages (A, B, C, D, E, and F) were found in animals, and assemblage B was frequently recorded in human and monkey populations, whereas assemblages A and E were predominant in calves. Assemblage A was found in sika deer and assemblages A, C, D, and F were predominant in dogs, cats, and ferret. Eimeria bovis, E. zuernii, and other species found in animals made up the group of species known as Eimeria spp., with E. bovis and E. zuernii being the most common in cattle. Our review highlighted a notable lack of data investigations regarding these two pathogens in water and environmental sources. Giardia cysts were found in the few studies that have been done on water sources, suggesting that water may play a significant role in the transmission of Giardia species. Our review suggests that further research is necessary to fully comprehend the molecular diversity and dynamics of transmission of Giardia spp. and Eimeria spp. in humans, animals, and environmental sources in Japan.

Diagnosis of fasciolosis antibodies in Brazilian cattle through ELISA employing both native and recombinant antigens

Bovine fasciolosis is a parasitic disease with a global reach. Coprological based on egg detection in fecal samples and liver inspection to evaluate the presence of the parasite is currently the gold standard for diagnosing chronic fasciolosis in cattle. However, these techniques are labor-intensive and ineffective during the acute phase of the disease. Serodiagnosis using native and recombinant antigens has become an interesting alternative in efforts to identify cattle fasciolosis. We evaluated cattle from abattoir (n = 139) and farms (n = 500) through liver inspection and coprological examination, respectively. Our laboratory team optimized and validated enzyme-linked immunosorbent assay tests based on somatic antigen, excretory/secretory proteins, and the recombinant antigen cathepsin L-1 to detect serum antibodies against fasciolosis in cattle. For animals from abattoir, 10 were positive for fasciolosis according to liver inspection. Both FhES and FhrCL-1 presented an area under the receiver operating characteristic (AUROC) curve of 0.80, with a sensitivity of 0.80 (95% CI: 0.46-0.95) and 0.70 (95% CI: 0.38-0.90) and specificity of 0.81 (95% CI: 0.73-0.87) and 0.87 (95% CI: 0.80-0.92), respectively. For those cattle from farms, 28 were positive only for fasciolosis according to coprological examination. In this scenario, FhES gave the best performance, with an AUROC of 0.84, sensitivity of 0.79 (95% CI: 0.60-0.90), and specificity of 0.86 (95% CI: 0.82-0.89). In conclusion, our study highlights the potential of serodiagnosis for accurately screening cattle fasciolosis. The promising sensitivity and specificity values of FhES when compared to liver inspection or coprological examination enhance its importance for cattle fasciolosis diagnosis.

IMPORTANCE

The aim of this article was to identify antibodies against fasciolosis in cattle in Brazil. The methodology was reproduced in our laboratory and applied for the first time to the Brazilian cattle herd. The antigens tested can be used as a screening test and thus speed up the diagnosis of bovine fascioliasis.

Fresh Leafy Vegetables and Parasitic Contamination: Practical Solutions

This study aimed at investigating the parasitic contamination of fresh leafy vegetables in Tehran, Iran, during 2020-2021. A cross-sectional study was conducted and 180 fresh leafy vegetables (including leek, watercress, mint, spring onion, radish, basil, parsley, lettuce, and spinach) were collected randomly in the five regions of Tehran, Iran. Each 200-g sample was soaked with tap water containing detergent, and the obtained sediment was centrifuged and examined for parasitic stages using a light microscope. The overall rate of parasitic contamination was 19.4%, with Trichostrongylus and Toxocara eggs being the most prevalent parasites (3.9%) and the highest rate of parasitic contamination was observed in spinach (40%), whereas no contamination was found in spring onions. Except for radish, other vegetable samples had multiple parasitic infections. Due to the contamination of vegetables, it is necessary to have a suitable method to reduce the parasites. Consequently, policymakers should safeguard public health by consistently monitoring contaminants in food and prioritizing education and research on methods to mitigate their presence in the food chain.

Deciphering the epidemiological dynamics: Toxoplasma gondii seroprevalence in mainland China's food animals, 2010-2023

Background

Toxoplasma gondii (T. gondii) is a significant protozoan pathogen among food animals. Despite the threat to public health by T. gondii infections, there's limited understanding of its seroprevalence and trends in food animals across mainland China. This study aimed to estimate the seroprevalence of T. gondii infections among swine, sheep, goats, chickens, and cattle in mainland China from 2010 to 2023.

Methods

We searched cross-sectional studies published between 2010 and 2023 that reported the prevalence of T. gondii in food animals from databases including PubMed, Embase, Web of Science, China Biology Medicine Disc (CBM), China National Knowledge Infrastructure (CNKI), Wanfang data, and the China Science and Technology Journal Database (CQVIP). We performed subgroup analyses to explore the impact of different factors on the seroprevalence of T. gondii. Pooled estimates of T. gondii seroprevalence were calculated with a random-effects model.

Results

An analysis of 184 studies involving 211985 animals revealed a T. gondii overall seroprevalence of 15.3% (95% CI: 13.1-17.8). Although the seroprevalence of food animals across mainland China was relatively stable from 2010 to 2023, notable variations were observed across different animal types and regions (P < 0.01), along with changes in geographical distribution. Sample type, detection method, animal age, and history of abortion were identified as key risk factors for T. gondii seroprevalence.

Conclusion

The study conducted a meta-analysis on the seroprevalence of T. gondii in mainland China's Food Animals from 2010 to 2023, and identified key risk factors. These findings advance our understanding of T. gondii infection dynamics, offering critical insights for developing control strategies and guiding public health policies.

Nexus between prevalence of Taenia solium (Cysticercus cellulosae) in pigs and retrospective study of humans cysticercosis cases in Benin hospitals

The cysticercosis is a major zoonotic disease in many developing countries. This study was carried out to determine the prevalence of porcine cysticercosis and to identify potential risk factors associated and their seroprevalence as well in Benin. The tongue palpation was performed on 4150 pigs from the pig farmers were randomly selected to diagnose cysticercosis and to assess the risk factors associated. In slaughterhouses, 792 pigs were inspected. Serum samples from 460 pigs were tested of the presence of Taenia solium cysticercosis using the HP10 antigen-ELISA (Ag-ELISA). A logistic regression model with a 95% confidence interval was used to analyse the main risk factors associated. The tongue palpation revealed a prevalence of 4.79% at the level of slaughterhouses versus 7.82% in the post-mortem inspection. The Ag-ELISA revealed that more than 40% of the pigs were positive. The risk factors identified were the origin area of pigs, the history of cysticercosis in the farms, the presence or absence of a latrine, the pig-farming systems, the age class of pigs and the source of watering. In addition, 34.48% individuals was tested for taenia versus 13.79% for cysticercosis in the hospitals surveyed. Our results showed the major revelation of porcine cysticercosis and its very high level of risk for a public health in all departments of Benin. Therefore, this study suggests the need to continue epidemiological and sociological surveys with a "One Health" approach in order to design and implement effective control measures in this country of high consumption of pigs.

Digenean infections in snails (cercariae stage) in Can Gio Mangrove Biosphere Reserve, Ho Chi Minh City, Vietnam

Foodborne zoonotic trematodiasis is a public health problem in many countries. A study on digenean larvae (cercariae stage) obtained from snails in all ten main small canals and two rice fields was carried out in Can Gio Mangrove Biosphere Reserve, Ho Chi Minh city, Vietnam to identify the snail composition and digenean prevalence in snails. The snails were sampled in the dry season (January 2022) and the wet season (June 2022). In the ten canals, 23 snail species belonging to 16 genera, 10 families from the samplings were found; however, there were no cercariae in these 23 snail species. In the two rice fields, 11 snail species in 11 genera and 7 families were collected. In which, Bithynia siamensis in Ly Nhon rice field and Thiara scabra in Binh Khanh rice field infected xiphidio cercariae. For Bithynia siamensis, the prevalence in the dry season (5.6%) was higher than in the wet season (4.6%) (P > 0.05). In Binh Khanh rice field, only one Thiara scabra infected cercariae in the wet season. Further research on digenean infection in different months and in other water bodies in Can Gio Mangrove Biosphere Reserve should be done to contribute to the control of digeneans and reserve the biodiversity.

Advances in the Development of Carbonic Anhydrase Inhibitors as New Antiprotozoal Agents

BACKGROUND

Parasitic diseases are a public health problem despite the existence of drugs for their treatment. These treatments have variable efficacy and, in some cases, serious adverse effects. There has been interest in the enzyme carbonic anhydrase (CA) in the last two decades since it is essential in the life cycle of various parasites due to its important participation in processes such as pyrimidine synthesis, HCO3 - transport across cell membranes, and the maintenance of intracellular pH and ion transport (Na+, K+, and H+), among others.

OBJECTIVE

In this review, CA was analyzed as a pharmacological target in etiological agents of malaria, American trypanosomiasis, leishmaniasis, amoebiasis, and trichomoniasis. The CA inhibitors´ design, binding mode, and structure-activity relationship are also discussed.

CONCLUSION

According to this review, advances in discovering compounds with potent inhibitory activity suggest that CA is a candidate for developing new antiprotozoal agents.

Surveillance and control of Trypanosoma evansi in the canary Islands: A descriptive analysis

This study examines the occurrence of Surra, a disease caused by Trypanosoma evansi, in camels in the Canary Islands. The 1997 detection of T. evansi in camels in the Canary Islands led to the implementation of an initial control program, resulting in a decrease in prevalence. Following an outbreak in 2014, and due to the impossibility of eradicating it using the conventional measures, a lazaret was set up to separate positive and suspicious animals, in addition to the control measures previously implemented. Stomoxys calcitrans was the only vector captured, and no other animals tested were found to be positive for T. evansi. In November 2019, the last camels that tested serologically positive were detected; however, since February 2018, no camels that tested positive for PCR have been found in the farms were the outbreak was detected, suggesting that the sanitary measures implemented are adequate. The duration of the outbreak control and potential eradication for the disease has yet to be established. This study provides evidence to facilitate the control of African Animal Trypanosomosis in endemic areas of the world, which may contribute to revise the World Organization for Animal Health (WOAH) protocol to implement recommendations of surveillance and control strategies for animal Trypanosomosis in camels.

Parallel detection of multiple zoonotic parasites using a real-time fluorogenic loop-mediated isothermal amplification-based quadruple-sample microfluidic chip

Zoonotic parasites pose significant health risks globally. In the present study, we combined a microfluidic chip with loop-mediated isothermal amplification (on-chip LAMP) to detect five zoonotic parasites: Toxoplasma gondii, Cryptosporidium parvum, Cryptosporidium hominis, Clonorchis sinensis, and Taenia solium. This method enabled the simultaneous parallel analysis of five genetic markers from a maximum of four samples per chip. The on-chip LAMP assay was conducted in a highly automated format via the addition (by pipetting) of each sample in a single operation. The reaction was performed in volumes as low as 5 μL at a temperature of 65°C for 60 min, achieving limits of detection ranging from 10-2 to 10-3 pg./μL of recombinant plasmid DNA. All the time-to-positive values were less than 40 min, and almost all the coefficients of variation were less than 10%, even when using limit of detection concentrations for multiple pathogens, indicating robust reproducibility among replicates. The clinical sensitivity and specificity for detecting 135 field samples were 98.08 and 97.59%, respectively, compared with traditional biological methods, indicating good applicability in the detection of field samples. This on-chip LAMP assay allows for low reagent consumption, ease of operation, and multiple analyses of samples and genetic targets, and is applicable for on-site detection and the routine monitoring of multiple zoonotic parasites.

The prevalence and molecular detection of bovine cysticercosis and its impact on slaughtered cattle in Egypt

Cysticercus bovis is the metacestode of the commonly defined foodborne cestode, Taenia saginata. It infects heart, masseter muscles and other muscular sites of cattle causing bovine cysticercosis. So, a retrospective study using archival documents from authorized agencies is done during the period of 2018-2020 with estimating economic losses. Cysts were collected from municipal Beni-Suef and Basatin abattoirs. Molecular approach including cPCR and sequencing analysis is used to prove the species. The prevalence was 0.34% in Beni-Suef abattoir and 5.70% in Basatin abattoir including heads, hearts or all carcasses condemned. Among 27 provinces surveyed, the highest prevalence was recorded in Aswan followed by Cairo, Suez and Red Sea. Moreover, 19 provinces (Cairo, Alexandria, Suez, Dakahlia, Sharkia, Qalyobia, Kafrelsheikh, Gharbia, Menofiya, Ismailia, Giza, Beni-Suef, Assiut, Sohag, Qena, Aswan, Red Sea, South Sinai and El-Wadi El-Gadid) recorded bovine cysticercosis in 2018, 2019 and 2020. On the other hand, Luxor and North Sinai had no infections. The percentages of condemnation among slaughtered cattle were 1.38, 1.49 and 0.87% in 2018, 2019 and 2020, respectively. Condemnations significantly varied among north, middle and south districts of Egypt, and also varied annually. Molecularly, a diagnostic band at an amplicon size 253 bp targeting the COI gene specific for Cycticercus bovis was revealed. The obtained sequences showed 100% identity with the different Taenia saginata COI GB sequence isolates in many countries worldwide. The phylogenetic analysis method showed that the obtained sequences originating from the same clade of Taenia saginata GB isolates globally. Careful meat inspection as well as strict hygienic measures is recommended for both veterinarians and public.

Serological survey of Toxoplasma gondii infection in the one-humped camels (Camelus dromedarius) in the south of Iran

BACKGROUND

Toxoplasmosis, an important zoonotic disease, is caused by Toxoplasma gondii. Camels are one of several host species for T. gondii parasites and play an important role in the transmission of T. gondii to humans.

OBJECTIVES

The present study aimed to describe the seroprevalence of T. gondii in dromedary camels (Camelus dromedarius) from three provinces (Fars, Bushehr and Hormozgan), southern Iran first for this host.

METHODS

A total of 180 serum samples were analysed for the presence of anti-Toxoplasma IgG antibodies using the enzyme-linked immune-sorbent assay.

RESULTS

Our results showed an overall seroprevalence of T. gondii in 15% of animals. Antibodies to T. gondii were found in sera of 27 of 180 dromedary camels from Fars, Bushehr and Hormozgan provinces, southern Iran. Age or the gender of the camel did not significantly affect the seroprevalence (p > 0.05). There was no significant association between herd-level seroprevalence of T. gondii infection and abortion history, province location residence, history of animal keeping and history of contact with other animals (p > 0.05).

CONCLUSIONS

The results of this study showed the presence of T. gondii antibodies among camels in Southern Iran, which could be a public health concern. According to the prevalence of T. gondii infection in camel, the implementation of control measures to reduce infection in both definitive and intermediate hosts is needed.

Albumin nanostructure assisted ABZ anti-parasite immune therapy for T. spiralis muscle infection

Currently, the treatment of Trichinella spiralis (T. spiralis) intracellular infection by oral administration of albendazole (ABZ) is hampered by its poor aqueous solubility and rapid metabolism. Herein, the nanoparticles with BSA and ABZ (ABZ-BSA Nps) were constructed by a desolvation technique in the study. The anti-parasite activity and pharmacokinetics of ABZ-BSA Nps were evaluated for T. spiralis muscle larvae during the encysted phase. The immune-responsive cytokines of ABZ-BSA Nps were quantitatively analyzed. The results showed that ABZ-BSA Nps could eliminate the muscle larvae by triggering the unbalance of Th1/Th2 immune-response in the infection mice. For ABZ-BSA Nps treatment group, the plasma concentration of ABZSO (ABZ active metabolite) was higher than ABZ and the muscle larvae were reduced by 70.2 %. In conclusion, the study had constructed a successful prospective protein nanoparticle delivery ABZ and evidenced the ABZ could be used for intracellular parasite therapy by triggering the anti-parasite immunity of hosts.

An epidemiological survey of porcine cysticercosis in Rungwe District, Tanzania

Taeniasis/cysticercosis caused by tapeworms belonging to the genus Taenia, poses serious veterinary and public health problems, resulting in economic burden in endemic low-income countries worldwide. However, little epidemiological data exist on infection status among pigs in many areas in Tanzania. We conducted a cross-sectional survey in Rungwe District, Mbeya Region, Tanzania, to define the prevalence and risk factors associated with porcine cysticercosis transmission. One-hundred sixty-nine pigs from 152 households were examined for circulating taeniid antigens by cysticercosis antigen (Ag) enzyme-linked immunosorbent assay (ELISA). Agarose gel electrophoresis was used to differentially diagnose Taenia species-specific cysticerci DNA bands. Structured questionnaires were administered in the surveyed households to collect information on risk factors for porcine cysticercosis transmission. Sera from eleven household pigs tested positive for porcine cysticercosis in the Ag-ELISA with an apparent prevalence of 6.5 % (95 % C.I. 3.8-11.3 %) and estimated true prevalence of 6.1 % (95 % C.I. 3.3-10.9 %). DNA Gel electrophoresis confirmed that 100 % of cysticerci isolated amongst pigs slaughtered in the study area belonged to T. solium. Of the five surveyed wards, positive household pigs were from Bulyaga, Kiwira, and Mpuguso. Lack of knowledge on porcine cysticercosis among household members was found to be significantly associated with positivity of Taenia species antigen in pigs sera (OR = 7.742, p = 0.017). Our results show that porcine cysticercosis is prevalent in Rungwe. There is a definite need to establish control measures against this potential zoonosis to safeguard veterinary and public health in the Rungwe District.

Zoonotic helminths - why the challenge remains

Helminth zoonoses remain a global problem to public health and the economy of many countries. Polymerase chain reaction-based techniques and sequencing have resolved many taxonomic issues and are now essential to understanding the epidemiology of helminth zoonotic infections and the ecology of the causative agents. This is clearly demonstrated from research on Echinococcus (echinococcosis) and Trichinella (trichinosis). Unfortunately, a variety of anthropogenic factors are worsening the problems caused by helminth zoonoses. These include cultural factors, urbanization and climate change. Wildlife plays an increasingly important role in the maintenance of many helminth zoonoses making surveillance and control increasingly difficult. The emergence or re-emergence of helminth zoonoses such as Ancylostoma ceylanicum, Toxocara, Dracunculus and Thelazia exacerbate an already discouraging scenario compounding the control of a group of long neglected diseases.

Foodborne Parasites and Their Complex Life Cycles Challenging Food Safety in Different Food Chains

Zoonotic foodborne parasites often represent complex, multi host life cycles with parasite stages in the hosts, but also in the environment. This manuscript aims to provide an overview of important zoonotic foodborne parasites, with a focus on the different food chains in which parasite stages may occur. We have chosen some examples of meat-borne parasites occurring in livestock (Taenia spp., Trichinella spp. and Toxoplasma gondii), as well as Fasciola spp., an example of a zoonotic parasite of livestock, but transmitted to humans via contaminated vegetables or water, covering the 'farm to fork' food chain; and meat-borne parasites occurring in wildlife (Trichinella spp., Toxoplasma gondii), covering the 'forest to fork' food chain. Moreover, fish-borne parasites (Clonorchis spp., Opisthorchis spp. and Anisakidae) covering the 'pond/ocean/freshwater to fork' food chain are reviewed. The increased popularity of consumption of raw and ready-to-eat meat, fish and vegetables may pose a risk for consumers, since most post-harvest processing measures do not always guarantee the complete removal of parasite stages or their effective inactivation. We also highlight the impact of increasing contact between wildlife, livestock and humans on food safety. Risk based approaches, and diagnostics and control/prevention tackled from an integrated, multipathogen and multidisciplinary point of view should be considered as well.

Factors associated with meat hygiene-practices among meat-handlers in Metropolitan City of Kathmandu, Nepal

Meat hygiene refers to all conditions and measures necessary to ensure safety and suitability of meat at all stages of the food chain. Inadequate hygiene practices allow consumers to be exposed to pathogens causing public health problems. Inadequate facilities and hygiene practices in meat shops results in meat contamination. The study aimed to identify factors associated with meat hygiene practices among meat handlers in the Metropolitan City of Kathmandu, Nepal. A cross-sectional study was designed with a semi-structured questionnaire and observation checklist that collected information about hygiene practices from 320 consenting meat-handlers by interviewer-administered technique. Data was entered in EpiData and analyzed using IBM SPSS version 21. Descriptive statistics of frequency distribution were used to report meat hygiene-practices and other independent variables, with multivariate logistic regression to establish predictors of meat hygiene-practices at 5% level of significance. The study revealed that less than half (44.4%) of the meat handlers had satisfactory meat hygiene practices. The adjusted regression analysis showed, strong evidence (p<0.01) of association of higher education level (AOR = 2.8, 95% CI = 1.7-4.5), other occupational involvement (AOR = 2.2, 95% CI = 1.9-2.4), and being officially registered (AOR = 2.8, 95% CI = 1.2-6.8) with meat hygiene practices. However, there was fair evidence (p<0.05) of association between shorter duration of meat being processed to sale (AOR = 0.57, P = 0.042) and meat hygiene practices. In this study, the satisfactory meat hygiene practices of meat handlers was low. The educational level, registration status of shops, involvement in other jobs, and awareness on meat hygiene were identified as key factors associated with meat hygiene practices. Thus, these factors need to be considered while developing programs to improve meat hygiene practices among the meat handlers. Meat handlers should be provided with training and orientation program for improving the meat hygiene practices.

Protozoa as the “Underdogs” for Microbiological Quality Evaluation of Fresh Vegetables

The monitoring of the microbial quality of fresh products in the industrial environment has mainly focused on bacterial indicators. Protozoa, such as Giardia duodenalis, Cryptosporidium spp., Toxoplasma gondii, and Cyclospora cayetanensis, are routinely excluded from detection and surveillance systems, despite guidelines and regulations that support the need for tracking and monitoring these pathogens in fresh food products. Previous studies performed by our laboratory, within the scope of the SafeConsume project, clearly indicated that consumption of fresh produce may be a source of T. gondii, thus posing a risk for the contraction of toxoplasmosis for susceptible consumers. Therefore, preliminary work was performed in order to assess the microbiological quality of vegetables, highlighting not only bacteria (Escherichia. coli, Listeria monocytogenes, and Salmonella spp.), but also the zoonotic protozoa G. duodenalis and Cryptosporidium spp. Although all samples were found to be acceptable based on bacteriological parameters, cysts of G. duodenalis and oocysts of Cryptosporidium spp. were observed in vegetables. Moreover, it was possible to genetically characterize G. duodenalis positive samples as assemblage A, a genotype that poses risks to human health. Although these are preliminary results, they highlight the need to include protozoa in the microbiological criteria for foodstuffs, as required by EU Law No. 1441/2007, and to improve inactivation and removal procedures of (oo)cysts in fresh produce and water.

Occurrence of Taeniidae in a Middle Pleistocene speleothem of the Bàsura cave (Toirano, Liguria, Italy)

OBJECTIVE

This study aims to (i) analyse whether speleothems may contain fossil parasitic worm eggs and, if so, (ii) identify the pathogens involved, and (iii) place them in geological, palaeontological, and chronological contexts to know the zoonoses that could affect human and animal populations during the Middle Pleistocene.

MATERIALS

A sample of calcite dated to the beginning of MIS 9 and MIS 8 from the Bàsura cave (Liguria, Italy) was analysed.

METHODS

The chemical protocol applied is characterised using hydrochloric acid, the reduction of hydrofluoric acid application time, and by the absence of the use of base, dense liquor or acetolysis.

RESULTS

An embryophore of a taeniid was recovered.

CONCLUSIONS

Endoparasitic worm eggs can be found in speleothems. A taeniid embryophore was found in a calcite level dated to MIS 9. Zoonoses related to the Taeniidae family existed 300,000 years ago in the northern Mediterranean region and may have affected Middle Pleistocene predators, carnivores, or humans. Speleothems are good tools for paleoparasitological studies.

SIGNIFICANCE

This is the oldest taeniid recovered and identified.

LIMITATIONS

A more precise determination of the genus of this taeniid is not possible in the absence of more precise palaeontological data.

SUGGESTIONS FOR FURTHER RESEARCH

An application of this approach to other Pleistocene speleothems could broaden the spectrum of parasites and their zoonoses over remote Pleistocene periods.

Zoonotic diseases of fish and their prevention and control

Fish and aquatic-derived zoonotic diseases have caused considerable problems in the aquaculture industry and fishery worldwide. In particular, zoonotic diseases can pose widespread threats to humans. With the world’s growing population and potential global trade of aquaculture and fish, the risk of environmental contamination and development of fish and aquatic-derived zoonoses in humans are increasing. The important causes of zoonoses include bacteria, parasites, viruses, and fungi. The zoonotic bacterial agents are divided into two main groups: Gram-positive (Mycobacteriaceae, Streptococcaceae, Erysipelothricaceae families) and Gram-negative (Aeromonadaceae, Vibrionaceae, Pseudomondaceae, Enterobacteriaceae, and Hafniaceae families). The premier parasitic agents include cestodes (tapeworm; e.g. Diphyllobothrium spp.), trematodes (fluke; e.g. Opisthorchis spp.), and nematodes (round worm; e.g. Anisakis spp.). In addition, protozoan organisms such as Cryptosporidium spp. are also considered fish-derived zoonotic pathogens. Two groups of fish-associated fungi causing basidiobolomycosis and sporotrichosis also pose a zoonotic risk for humans. The majority of the fish-derived zoonotic diseases are transmitted to humans mainly via the consumption of improperly cooked or raw fish or fish products. Therefore, the incidence of zoonotic diseases can be reduced by properly processing fish and fish products, e.g. by thermal (heat/freezing) treatment. The prevalence of zoonotic agents in fishes varies seasonally and should be regularly monitored to evaluate the prevalence of pathogens in both wild and cultured fish populations. This review focuses on the fish zoonotic agents/diseases and their control and prevention.

The implementation of the Kinyoun staining technique in a resource-limited setting is feasible and reveals a high prevalence of intestinal cryptosporidiosis in HIV patients

OBJECTIVES

In resource-limited settings, intestinal Cryptosporidia or coccidian infections are common causes of chronic diarrhoea, but usually remain undiagnosed by routine stool investigation. Here, the addition of the Kinyoun staining technique after stool concentration was evaluated as an easy and inexpensive method for diagnosis of intestinal parasitic infection in HIV-infected patients.

METHODS

This cross-sectional study investigated HIV-infected patients with diarrhoea and randomly selected HIV-infected patients without diarrhoea as controls. Stool samples were examined by wet mount microscopy and Kinyoun staining after stool concentration. Clinical, sociodemographic and behavioural data were collected. Statistical analysis was performed using Chi-squared test and multivariate regression analysis.

RESULTS

In total, 163 participants were included (62.0% female, mean age 38.2 [SD ±10.7] years). Diarrhoea was present in 52.1% (85/163). The prevalence of intestinal parasites was 18.4% (30/163). Cryptosporidia infections were more frequent among patients with diarrhoea (12.9% [11/85] vs. 1.3% [1/78], p=0.005) and in patients with CD4⁺ cell count <200 cells/µL (25.9% [7/27] vs. 3.7% [5/136], p=0.001). Risk factors for intestinal parasitic infections were diarrhoea and the habit of regularly eating uncooked food. Kinyoun staining was necessary for detection of cryptosporidiosis.

CONCLUSION

In our cohort, the prevalence of intestinal parasitic infection was high, especially after additional utilization of Kinyoun staining for detection of Cryptosporidia or intestinal coccidia. Considering its clinical relevance particularly in individuals at risk, the implementation of this technique should be considered in resource-limited settings.

A large-scale epidemiological investigation on trematode infections in small ruminants in Bangladesh

BACKGROUND

The important trematode species in small ruminants: Paramphistomum sp., Fasciola spp. and Schistosoma spp. seriously affect the productivity of domestic ruminants in endemic areas.

METHODS

In the present study, we identified the potential risk factors associated with trematodes infections in small ruminants in seven topographic zones of Bangladesh using simple sedimentation and modified Stoll' ova counting technique.

RESULTS

A total of 2440 samples were examined, where 965 were found positive with one or more trematode species with an overall prevalence of 39.5% (95% CI, 37.6%-41.5%) and intensity of infection was 264.77 ± 9.86 egg per gram of faeces. Three trematode species were identified namely Paramphistomum sp. (34.1%, 32.2%-36.0%), Fasciola spp. (7.5%, 6.5%-8.6%) and Schistosoma spp. (2.7%, 2.1%-3.5%). Prevalence of co-infection was 4.8%. The spatial distribution of trematode infections varied from 29.5% to 53.6%. Univariate analysis revealed that physiological condition of females, body condition, farming system, deworming and season were significantly (p < 0.05) associated with trematodes infections in small ruminants. By multiple logistic regression model, three factors such as physiological condition of females (pregnant and lactating), poor body condition and animals without deworming were identified as potential risk factors for trematodes infection in small ruminants.

CONCLUSION

Trematode infections are prevalent in the study areas and Paramphistomum sp. is most common in different areas among the identified trematodes species. Government should take necessary action to appraise an effective control strategy of trematode infections in small ruminants.

Environmental contamination with parasites in selected rural farms in the Philippines: impacts of farming practices on leafy greens food safety

Fresh vegetables are an important part of a healthy diet, however, they can also be agents of transmission of intestinal parasites. This study aimed to evaluate the presence of parasite contamination in vegetable farms as a source of transmission in selected rural communities in Laguna, Philippines. A total of 168 vegetable, 55 soil and 15 water samples collected from four selected farms and a reference farm were processed through various standard parasitological techniques. Of these, 17.3% of vegetables, 47.3% soil and 73.3% water samples were found contaminated with parasites’ eggs or cysts. Interestingly, leafy vegetables, such as lettuce, were found to be more contaminated. Results showed that strongylids/hookworms (egg/larva) showed the highest prevalence in farm soil (38.2%) and vegetable (13.1%); other helminth parasite eggs were also recovered such as Toxocara sp., Ascaris sp., Trichiuris, Trichostrongylus sp. and protozoan cysts of Balantidium coli. Cryptosporidium sp. oocysts of and Giardia sp. cysts were observed in all water samples in the farms. Furthermore, results revealed that some farming practices such as the use of improperly treated animals manure as fertilizers, unhygienic practice of farmers and sanitation issues were factors that contribute to parasite contamination in the farms. These findings have implications on food safety in poor-resource communities posing public health risks. Recommendations were discussed in the study for the control and prevention of parasite contamination at the farm level.

A review of the molecular epidemiology of Cryptosporidium spp. and Giardia duodenalis in the Middle East and North Africa (MENA) region

Cryptosporidium spp. and Giardia duodenalis are important protozoan parasites which are associated with diarrheal diseases in humans and animals worldwide. Relatively little is known about the molecular epidemiology of Cryptosporidium spp. and Giardia duodenalis in the Middle East Countries and North Africa (MENA region). Therefore, this review aimed to inspect published genotyping and subtyping studies on Cryptosporidium spp. and Giardia duodenalis in the MENA region. These studies indicate that both anthroponotic and zoonotic transmission of Cryptosporidium occurs with the predominance of zoonotic transmission in most countries. Seven Cryptosporidium species were identified in humans (C. parvum, C. hominis, Cryptosporidium meleagridis, C. felis, Cryptosporidium muris, C. canis and C. bovis), with C. parvum by far being the most prevalent species (reported in 95.4% of the retrieved studies). Among C. parvum gp60 subtype families, IIa and IId predominated, suggesting potential zoonotic transmission. However, in four MENA countries (Lebanon, Israel, Egypt and Tunisia), C. hominis was the predominant species with five subtype families reported including Ia, Ib, Id, If and Ie, all of which are usually anthroponotically transmitted between humans. In animals, the majority of studies were conducted mainly on livestock and poultry, 15 species were identified (C. parvum, C. hominis, C. muris, Cryptosporidium cuniculus, C. andersoni, C. bovis, C. meleagridis, C. baileyi, C. erinacei, C. ryanae, C. felis, C. suis, Cryptosporidium galli, C. xiaoi and C. ubiquitum) with C. parvum (IIa and IId subtypes) the dominant species in livestock and C. meleagridis and C. baileyi the dominant species in poultry. With G. duodenalis, five assemblages (A, B, C, E and F) were identified in humans and six (A, B, C, E, D and F) in animals in MENA countries with assemblages A and B commonly reported in humans, and assemblages A and E dominant in livestock. This review also identified a major knowledge gap in the lack of Cryptosporidium spp. and Giardia duodenalis typing studies in water and food sources in the MENA region. Of the few studies conducted on water sources (including drinking and tap water), ten Cryptosporidium species and four genotypes were identified, highlighting the potential role of water as the major route of Cryptosporidium spp. transmission in the region. In addition, three G. duodenalis assemblages (A, B and E) were detected in different water sources with AI, AII and BIV being the main sub-assemblages reported. More research is required in order to better understand the molecular diversity and transmission dynamics of Cryptsporidum spp. and Giardia duodenalis in humans, animals, water and food sources in MENA region.

Geospatial epidemiology of Toxoplasma gondii infection in livestock, pets, and humans in China, 1984-2020

Undercooked or raw meat containing cyst-stage bradyzoites and oocyst-contaminated pets are presumed to constitute a major source of human toxoplasmosis. As the geospatial epidemiology of Toxoplasma gondii (T. gondii) infection in livestock, pets, and humans is rarely studied in China, we undertook a geospatial analysis using GIS visualization techniques. The present study retrieved information from the PubMed, China National Knowledge Infrastructure, and Baidu Scholar databases from 1984 up to 2020. All the data about the seroprevalence of T. gondii in livestock (sheep and goats, pigs, cattle and yaks), pets (cats, dogs), and humans in China were collected. Geospatial epidemiology of T. gondii infection in these hosts was performed using GIS. Results revealed that the estimated pooled seroprevalence of T. gondii was ranged from 3.98 to 43.02% in sheep and goats in China, 0.75 to 30.34% in cattle and yaks, 10.45 to 66.47% in pigs, 2.50 to 60.00% in cats, 0.56 to 27.65% in dogs, and 0.72 to 23.41% in humans. The higher seroprevalences of T. gondii were observed in sheep and goats in the districts of Chongqing, Zhejiang, and Beijing. The infection rates of T. gondii in cattle and yaks were higher in Guizhou, Zhejiang, and Chongqing. Also, the pigs from Chongqing and Guizhou were most severely infected with T. gondii. For cats, the districts of Shanxi, Hebei, and Yunnan had higher seroprevalences of T. gondii and, the infections among dogs were higher in Yunnan and Hebei as well. Furthermore, higher infection pressure of T. gondii exists in the districts of Taiwan and Tibet in humans. The geographical and spatial distribution of toxoplasmosis indicated that infection with T. gondii was widely spread in China, with a wide range of variations among the different hosts and regions in the country. Our results suggested that livestock and pets are not only a reservoir for the parasite but also a direct source of T. gondii infection for humans. It is important to control T. gondii infections in these animals that would reduce the risk of toxoplasmosis in humans.

Identification and functional characterization of the siRNA pathway in Taenia crassiceps by silencing Enolase A

A gene silencing procedure on cysticerci of the taeniid cestode Taenia crassiceps is described. This is the first time this technique is reported in this species that is widely used as an animal model for human cysticercosis. Genome database searches were performed in order to find out if relevant genes involved in gene silencing and non-coding RNA processing, Argonaute and Dicer (AGO and Dcr) are present in T. crassiceps. We found three AGO and two Dcr orthologues that were designed TcAGO1, Tc2 and Tc3, as well as TcDcr1 and TcDcr2. In order to elucidate the evolutionary relationships of T. crassiceps TcAGO and TcDcr genes, separate phylogenetic analyses were carried out for each, including AGO and Dcr orthologues of other 20 platyhelminthes. Our findings showed a close phylogenetic relationship of TcAGO and TcDcr with those previously described for Echinococcus spp. Our RT-PCR studies demonstrated expression of all TcAGO and TcDcr orthologues. Our results show that the gene silencing machinery in T. crassiceps is functionally active by inducing silencing of TcEnoA (∼90%). These results clearly show that gene silencing using siRNAs can be used as a molecular methodology to study gene function in taeniid cestodes.

Human fascioliasis in Africa: A systematic review

Fascioliasis is a globally distributed, parasitic zoonosis, caused by Fasciola hepatica and F. gigantica. A comprehensive overview of the epidemiology of human fascioliasis in Africa is missing up to now. Therefore, our objective was to conduct a systematic review aiming to summarize recent knowledge on the distribution, prevalence, and risk factors of human fascioliasis in Africa. A key word search was performed in PubMed, Web of Science and Africa Wide, to gather relevant literature, published between the 1st of January 2000 and 31st of December 2020. A total of 472 records were initially retrieved, with 40 full text articles retained for the qualitative synthesis. Human fascioliasis was reported in 12 African countries, namely Algeria, Angola, Cape Verde, Egypt, Ethiopia, Ghana, Morocco, Nigeria, Senegal, South-Africa, Tanzania and Tunisia. The majority of the studies was conducted in Egypt. A total of 28 records were population surveys. Coproscopy was the most commonly used tool for fascioliasis diagnosis in these surveys. Gender (being female), consumption of raw vegetables/seeds, age, owning livestock, and use of unsafe drinking water sources, were identified as risk factors in 7 studies. Furthermore, 43 case reports were retrieved, described in 12 studies. Eosinophilia was present in 39 of these cases, while 11 had positive coproscopy results. Eight cases described having eaten raw wild vegetables. Overall, the low number and quality of records retrieved indicates that human fascioliasis remains a truly neglected disease in Africa, and more epidemiological studies are urgently needed to both establish the actual distribution as well as risk factors on the continent.

Raw meat based diet (RMBD) for household pets as potential door opener to parasitic load of domestic and urban environment. Revival of understated zoonotic hazards? A review

RMBD (acronym of Raw Meat Based Diet) and BARF diets (acronym for Biologically Appropriate Raw Food or Bones and Raw Food) account dietary regimens based on raw ingredients (including raw meat), popular in pet feeding. Animal tissues and organs as well as other uncooked ingredients are more and more popularly used by pet owners to feed household pets. However, the increased risk of exposure to microbiological and parasitic agents poses the question as to whether such diets may be recommendable to be handled and offered to domestic cats and dogs co-living in domestic and urban environment. Above all, the threat of human and animal infections by parasites from raw meat fed to pets is not sufficiently explored and tracked, meanwhile deserving particular surveillance, instead. At this regard, raw meat feeding to pets may represent a route of exposure to the increased risk of environmental load. In fact, some parasites typically found in rural environment can be given the chance to complete their life-cycle, for the closeness between definitive and intermediate hosts. This is of particular concern, as potentially infected pets serving as definitive hosts can become a continuous source of environmental diffusion of parasites, both at domestic and urban level. The handling of raw meat requires adequate knowledge and awareness of the hygienic principles to prevent the onset of disorders related to both manipulation by pet owners and uncooked food consumption by the pet. This review aimed to shed a comprehensive overview of the hygienic aspects related to raw pet feeding, as to handling of raw meat in domestic environment, with special emphasis on parasitic agents and related zoonotic hazards.

Risk Factors for Bovine Cysticercosis in North-West Italy: A Multi-Year Case-Control Study

Simple Summary

Bovine cysticercosis is a parasitic disease caused by Cysticercus bovis, the larval stage of the human tapeworm Taenia saginata, which is the causative agent of human taeniasis, a foodborne parasitic disease caused by the consumption of infected raw or undercooked beef meat. Although commonly asymptomatic, bovine cysticercosis has an important impact worldwide, causing huge economic losses to the meat industry due to carcass condemnation or downgrading. Given the lack of epidemiological case-control surveys carried out in Italy, the present survey’s aim was to assess the presence of farm-level risk factors for bovine cysticercosis in an endemic area in North-West Italy. The results of our survey show a significant association between the detection of bovine cysticercosis cases at slaughter and farm proximity to picnic spots, closeness of wastewater treatment plant effluents, presence of employees along with the family members and loose-housing systems. These findings highlight the need for enforced food chain information and surveillance strategies and the crucial role that hygiene-related campaigns would play to educate both the general public and farm operators on the transmission pathways of T. saginata.

Abstract

Taenia saginata is the causative agent of bovine cysticercosis, a zoonotic parasitic disease with a worldwide distribution. Bovine cysticercosis is considered to be an important food safety issue responsible for human taeniasis and a major economic concern since infected carcasses undergo condemnation, freezing and downgrading. The aim of the current investigation was to assess the presence of farm-level risk factors for bovine cysticercosis in an endemic area in North-West Italy. A questionnaire was designed to collect information relating to several farm structural features, as well as management practices, environmental characteristics and attitudes of farmers. The questionnaire was administered in two separate time intervals by direct interview to previously selected case and control farms. Overall, 32 case farms and 131 control farms were included between 2005 and 2011 and 50 case farms and 192 control farms were included between 2014 and 2020. The present survey showed a significant association between the detection of bovine cysticercosis cases at slaughter and farm proximity to picnic spots, closeness of wastewater treatment plant effluents, loose-housing systems and presence of employees along with the family members, highlighting the need for targeted awareness raising policies.

Brain food: rethinking food-borne toxocariasis

Human toxocariasis is a neglected tropical disease, which is actually global in distribution and has a significant impact on global public health. The infection can lead to several serious conditions in humans, including allergic, ophthalmic and neurological disorders such as epilepsy. It is caused by the common roundworm species Toxocara canis and Toxocara cati, with humans becoming accidentally infected via the ingestion of eggs or larvae. Toxocara eggs are deposited on the ground when infected dogs, cats and foxes defecate, with the eggs contaminating crops, grazing pastures, and subsequently food animals. However, transmission of Toxocara to humans via food consumption has received relatively little attention in the literature. To establish the risks that contaminated food poses to the public, a renewed research focus is required. This review discusses what is currently known about food-borne Toxocara transmission, highlighting the gaps in our understanding that require further attention, and outlining some potential preventative strategies which could be employed to safeguard consumer health.

The NF-κB Pathway: Modulation by Entamoeba histolytica and Other Protozoan Parasites

Protozoan parasites have led to worldwide devastation because of their ability to cause infectious diseases. They have evolved as successful pathogens in part because of their remarkable and sophisticated ways to evade innate host defenses. This holds true for both intracellular and extracellular parasites that deploy multiple strategies to circumvent innate host defenses for their survival. The different strategies protozoan parasites use include hijacking the host cellular signaling pathways and transcription factors. In particular, the nuclear factor-κB (NF-κB) pathway seems to be an attractive target for different pathogens owing to their central role in regulating prompt innate immune responses in host defense. NF-κB is a ubiquitous transcription factor that plays an indispensable role not only in regulating immediate immune responses against invading pathogens but is also a critical regulator of cell proliferation and survival. The major immunomodulatory components include parasite surface and secreted proteins/enzymes and stimulation of host cells intracellular pathways and inflammatory caspases that directly or indirectly interfere with the NF-κB pathway to thwart immune responses that are directed for containment and/or elimination of the pathogen. To showcase how protozoan parasites exploits the NF-κB signaling pathway, this review highlights recent advances from Entamoeba histolytica and other protozoan parasites in contact with host cells that induce outside-in and inside-out signaling to modulate NF-κB in disease pathogenesis and survival in the host.

Toxoplasma gondii Infection in Swine: Implications for Public Health

Toxoplasmosis, due to Toxoplasma gondii, is a parasitic disease with global importance. Among livestock, chronic T. gondii infection has been reported in higher rates in pigs and small ruminants, but with subclinical infections in case commonly encountered in pigs. Seroprevalence in the global pig population ranges according to the age or species of pigs, geographical distribution, production programs, and systems. Generally, T. gondii infections are noticed in low prevalence rates in conventional pig farms with high hygiene standards. In contrast, higher prevalence is common on free-ranging farms, outdoor or backyard small pig fams, as well as in farmed or hunted wild boars. The T. gondii average worldwide seroprevalence in pigs is reported to be 13% in Europe, 21% in Africa, 25% in North America, 21% in Asia, and 23% in South America. Human toxoplasmosis outbreaks have been correlated with the consumption of raw or undercooked meat, especially from infected pigs or wild boars, as well as of contaminated drinking water. The risk of infection in processed pork products is lower compared with fresh pork, as meat processing can reduce or inactivate T. gondii tissue cysts. Hence, the prevalence of T. gondii in the pig population may be a useful indicator of the risk of human toxoplasmosis associated with the consumption of pork products. The lack of obligatory screening methods at farm level for the detection of antibodies in farmed animals or the viable T. gondii in carcasses at slaughterhouse level increases the risk of contaminated pork or meat products. For this reason, the application of biosecurity and surveillance programs at farm level is very important to prevent a T. gondii infection.

Human Taeniasis and Cysticercosis and Related Factors in Phu Tho Province, Northern Vietnam

Several factors presumed to facilitate the transmission of Taenia spp. were reported in Vietnam. We conducted a cross-sectional study taking questionnaires from 1,185 participants, and collecting 1,151 sera and 1,036 stool samples in northern Vietnam. Sera were examined for circulating antigens of Taenia solium cysticerci using ELISA, stools for Taenia eggs by Kato-Katz smear, and copro-antigens by ELISA. Ag-ELISA revealed 4.6% antigen positivity, indicating infection with viable cysticerci. Taenia eggs were detected in 1.5% of participants. Copro-antigens were found in 2.8% of participants. Eating raw meat and/or vegetables was significantly associated with the presence of copro-antigen (OR=8.6, 95% CI: 1.16–63.9, P=0.01). Considering the high taeniasis prevalence and the associated threat, public health attention should be given to treat the tapeworm carriers in the projected areas.

A metabarcoding approach for detecting protozoan pathogens in wild oysters from Prince Edward Island, Canada

Food and waterborne protozoan pathogens including Cryptosporidium parvum, Giardia enterica and Toxoplasma gondii are a global concern for human public health. While all three pathogens have been detected in commercial shellfish, there is currently no standard approach for detecting protozoan parasites in shellfish. Common molecular and microscopic methods are limited in the number of pathogens they can simultaneously detect and are often targeted at one or two of these pathogens. Previously, we developed and validated a novel 18S amplicon-based next-generation sequencing assay for simultaneous detection of Cryptosporidium spp., Giardia spp. and T. gondii in shellfish. In this study, we applied the assay for protozoan pathogen detection in wild oysters from Prince Edward Island (PEI). Oysters were harvested from restricted and prohibited areas, classified by the Canadian government according to fecal coliform counts in surrounding waters, and different fractions (whole tissue homogenate and hemolymph) were analyzed. Protozoan DNA was detected using metabarcoding in 28%, of oysters tested (N = 128), and the pathogen read counts in oyster homogenate were considerably higher than those in hemolymph. Protozoan read count thresholds were established for classifying probable oyster contamination with pathogens to account for low levels of background protozoan reads detected in negative controls. Assay results showed protozoan contamination was not associated with harvesting site classifications, suggesting that using fecal indicators for ensuring food safety may be insufficient. Due to the complex matrix, an oyster DNA reduction step may further improve the pathogen detection sensitivity of the assay. Results from this study affirm that novel metabarcoding is a promising screening tool for detection of protozoan pathogens in shellfish.

Seroprevalence and Public Health Significance of Toxoplasmosis in Small Ruminants of Pastoral Community in Yabello District, Borana Zone, Southern Ethiopia

Toxoplasmosis is a zoonotic protozoan disease. Data on seroepidemiology of toxoplasmosis in Ethiopia is scarce, almost null in the pastoral area of the Borana zone. The study was carried out to determine the seroprevalence, to identify risk factors of toxoplasmosis in sheep and goats, and to assess the awareness level of pastoralists about toxoplasmosis in the Yabello district of Borana zone, Southern Ethiopia. A cross-sectional study was conducted from November 2016 to April 2017 in six peasant associations of the Yabello district of Borana zone, Southern Ethiopia. A total of 400 serum samples of randomly selected small ruminants owned by pastoralists were examined to detect antibodies specific to Toxoplasma gondii using Latex Agglutination Test (SPINREACT, Girona, Spain). A semistructured questionnaire survey was used to conduct a face-to-face interview with owners (n = 100) of sampled flocks. Logistic regression analysis was used to determine the association of hypothesized risk factors. The overall seroprevalence was 52.8% of which 57.8 and 47.8% were sheep and goats, respectively. Univariate logistic regression analysis revealed a higher seroprevalence ratio of T. gondii infection in sheep than goats (COR: 1.95, 95% CI: 1.226-3.112; P = 0.005). Multivariate logistic regression analysis indicated significantly higher odds of acquiring T. gondii infection in adult animals (sheep: (AOR = 2.26, 95% CI: 1.323-3.874; P = 0.003), goats: (AOR = 2.15; 95% CI: 1.009-4.579; P = 0.047)), female sheep (AOR = 2.45; CI: 1.313-4.568; P = 0.005), animals from lowland areas (sheep: (AOR = 2.28; CI: 1.190-4.356; P = 0.013), goat: (AOR = 3.27; CI: 1.386-7.723; P = 0.007)), animal drinking lake water (sheep: (AOR = 1.93; CI: 1.011-3.698; P = 0.046), goat: (AOR = 2.96; CI: 1.297-6.771; P = 0.010)), and goats with history of abortion (AOR = 2.42; CI: 1.242-4.711; P = 0.009) than young animals, male (sheep), animals from midland areas, animals drinking wells water, and flock with no history of abortion (goat), respectively. Among respondents, 97.0% had no knowledge about toxoplasmosis and 75.0% drink raw milk and consume the meat of sheep and goats. 80.0% of respondents had no knowledge about the risk of cats to human and animal health while 70.0% of them had domestic cats and practice improper fetal body handling. Highly prevailing toxoplasmosis in small ruminants of the Yabello district might pose a serious economic loss and be a potential public health threat to the extremely vulnerable pastoralists. Therefore, awareness and further studies are warranted to tackle the economic and public health consequences of T. gondii infection.

Prevalence of intestinal parasitic infections and Campylobacter spp. among children with gastrointestinal disorders in Tehran, Iran

Co-infection of intestinal parasitic infections (IPIs) and Campylobacter spp. are public health problem in both developing and developed countries. This study was conducted to determine prevalence of IPIs and Campylobacter spp. among children with gastrointestinal disorders in Tehran. In this descriptive cross-sectional survey, 283 fresh stool samples were collected from all individuals and examined by standard parasitological methods including direct slide smear, formalin-ether concentration, trichrome staining, modified Ziehl-Neelsen staining, and chromotrope 2R staining techniques were used for detection of intestinal protozoa and helminths. Furthermore, culture and multiplex-PCR were also used to identify the species of Campylobacter. Data analysis was performed using SPSS version 16. IPIs were detected microscopically in 22.26% of the total study population, with a higher prevalence in Giardia duodenalis (7.06%) and Blastocystis hominis (7.06%). Campylobacter were detected molecularly in 14.8% (95.2% of C. jejuni vs. 4.8% of C. coli) of the total study populations; of these, 3.5% had co-existence with IPIs colonized patients. Our results showed a relatively high prevalence of IPIs and Campylobacter in children with diarrhea. Further research is needed to better understand their co-infection and ensure future advances in clinical trials, testing, and development of therapeutic approaches for these pathogens.

Meat-borne parasites in the Arab world: a review in a One Health perspective

Meat-borne parasitic zoonoses are generally not well-monitored, and so understanding extent and overall prevalence is problematic. Without sufficient attention, their prevalence can become unexpectedly and unacceptably high. This review sheds light on meat-borne parasites in the Arab world, which includes all the Arab countries situated in the continents of Asia and Africa, with more than 400 million inhabitants distributed in 22 countries. Meat-borne parasites can be divided into two main categories-helminths and protozoa. The main helminths included in this review are Taenia saginata, Taenia solium, Taenia asiatica, Echinococcus spp., Fasciola spp., and Trichinella spiralis, while the meat-borne protozoan parasites are Toxoplasma gondii, Cryptosporidium spp., and Sarcocystis spp. In addition, Linguatula serrata, which belongs to the class Pentastomida, was included. Among those, the genus Taenia is the most frequently reported in the Arab world, particularly T. saginata. Many parasitic infections that are mainly transmitted through pork, although widespread in many parts of the world, are rare in the Arab countries, primarily due to religious proscriptions. The majority of the publications concerning meat-borne parasites were from Egypt, which contains the largest population in the Arab world and the highest population density, in addition to various economic, social, and environmental reasons.

Recent Developments in Recombinant Proteins for Diagnosis of Human Fascioliasis

Fascioliasis is an important neglected tropical disease that causes severe injury to the bile ducts and liver. Therefore, a rapid and accurate method for detection of Fasciola hepatica infection plays a vital role in early treatment. Currently, the diagnosis of fascioliasis is mainly conducted via serological tests using the excretory/secretory (E/S) products, which might cross-react with antigens from other helminth parasitic diseases. Hence, the development of serodiagnosis test using recombinant antigens may contribute to differentiate fascioliasis from other helminth infections. In the past 20 years, many attempts have been made to exert different F. hepatica recombinant antigens to obtain a well-established standard assay with high accuracy. In this review, we address recent studies that refer to the development of serodiagnosis tests for diagnosis of human fascioliasis based on the candidate recombinant antigens produced by different approaches. Meanwhile, in the present review, some main factors have been highlighted to improve the accuracy of diagnostic tests such as the effect of refolding methods to recover antigens' tertiary structure as well as applying a mixture of recombinant antigens with the highest sensitivity and specificity to improve the accuracy of diagnostic tests.

First morphological and molecular identification of third-stage larvae of Anisakis typica (Nematoda: Anisakidae) from marine fishes in Vietnamese water

Anisakid nematodes are parasites of cetaceans, their larval stages live in marine fishes. The third-stage larvae of some Anisakis species are also the etiological agents of human anisakiasis caused by consumption of raw or undercooked infected fish. Thus, identification of Anisakis larvae at the species level is crucial for their ecology and epidemiology. In Vietnam, although Anisakis larvae have been reported, they have not been identified to the species level. The aim of this study was, therefore, to identify third-stage larvae of Anisakis collected from marine fishes in Vietnamese water, based on morphological characteristics and molecular analysis. All Anisakis larvae found in this study were morphologically similar to each other and identical to Anisakis typica. In addition, molecular analysis based on ITS1-5.8S-ITS2 sequences confirmed them as A. typica. Vietnamese A. typica population was genetically close to those from Asian countries and Australia. The third-stage larvae of A. typica were collected from eight fish species from three localities in the South of Vietnam. Among them, seven were recorded as new intermediate hosts of A. typica. This is the first identification of A. typica larvae in Vietnamese water with records of new fish hosts.

Nosocomial Infections: Do Not Forget the Parasites!

Nosocomial infections (NIs) pose an increasing threat to public health. The majority of NIs are bacterial, fungal, and viral infections; however, parasites also play a considerable role in NIs, particularly in our increasingly complex healthcare environment with a growing proportion of immunocompromised patients. Moreover, parasitic infections acquired via blood transfusion or organ transplantation are more likely to have severe or fatal disease outcomes compared with the normal route of infection. Many of these infections are preventable and most are treatable, but as the awareness for parasitic NIs is low, diagnosis and treatment are often delayed, resulting not only in higher health care costs but, importantly, also in prolonged courses of disease for the patients. For this article, we searched online databases and printed literature to give an overview of the causative agents of parasitic NIs, including the possible routes of infection and the diseases caused. Our review covers a broad spectrum of cases, ranging from widely known parasitic NIs, like blood transfusion malaria or water-borne cryptosporidiosis, to less well-known NIs, such as the transmission of Strongyloides stercoralis by solid organ transplantation or nosocomial myiasis. In addition, emerging NIs, such as babesiosis by blood transfusion or person-to-person transmitted scabies, are described.

Human gnathostomiasis: a neglected food-borne zoonosis

BACKGROUND

Human gnathostomiasis is a food-borne zoonosis. Its etiological agents are the third-stage larvae of Gnathostoma spp. Human gnathostomiasis is often reported in developing countries, but it is also an emerging disease in developed countries in non-endemic areas. The recent surge in cases of human gnathostomiasis is mainly due to the increasing consumption of raw freshwater fish, amphibians, and reptiles.

METHODS

This article reviews the literature on Gnathostoma spp. and the disease that these parasites cause in humans. We review the literature on the life cycle and pathogenesis of these parasites, the clinical features, epidemiology, diagnosis, treatment, control, and new molecular findings on human gnathostomiasis, and social-ecological factors related to the transmission of this disease.

CONCLUSIONS

The information presented provides an impetus for studying the parasite biology and host immunity. It is urgently needed to develop a quick and sensitive diagnosis and to develop an effective regimen for the management and control of human gnathostomiasis.

Helminth Parasites among Rodents in the Middle East Countries: A Systematic Review and Meta-Analysis

Rodents can be a source of zoonotic helminths in the Middle East and also in other parts of the world. The current systematic review aimed to provide baseline data on rodent helminths to recognize the threats of helminth parasites on public health in the Middle East region. Following a systematic search on PubMed, Scopus, and Web of Science, a total of 65 research studies on rodent cestodes, nematodes, and trematodes, which were conducted in the countries of the Middle East, were analyzed. The study identified 44 rodent species from which Mus musculus, Rattus norvegicus, and Rattus rattus were most common (63%) and recognized as the primary rodent hosts for helminth infestation in this region. Cestodes were the most frequently reported (n = 50), followed by nematodes (49), and trematodes (14). The random effect meta-analysis showed that the pooled prevalence of cestode (57.66%, 95%CI: 34.63-80.70, l2% = 85.6, p < 0.001) was higher in Saudi Arabia, followed by nematode (56.24%, 95%CI: 11.40-101.1, l2% = 96.7, p < 0.001) in Turkey, and trematode (15.83%, 95%CI: 6.25-25.1, l2% = 98.5, p < 0.001) in Egypt. According to the overall prevalence estimates of individual studies, nematodes were higher (32.71%, 95%CI: 24.89-40.54, l2% = 98.6, p < 0.001) followed by cestodes (24.88%, 95%CI: 19.99-29.77, l2% = 94.9, p < 0.001) and trematodes (10.17%, 95%CI: 6.7-13.65, l2% = 98.3, p < 0.001) in the rodents of the Middle East countries. The review detected 22 species of helminths, which have zoonotic importance. The most frequent helminths were Capillaria hepatica, Hymenolepis diminuta, Hymenolepis nana, and Cysticercus fasciolaris. There was no report of rodent-helminths from Bahrain, Jordan, Lebanon, Oman, United Arab Emirates, and Yemen. Furthermore, there is an information gap on rodent helminths at the humans-animal interface level in Middle East countries. Through the One Health approach and countrywide detailed studies on rodent-related helminths along with their impact on public health, the rodent control program should be conducted in this region.

Food Safety Considerations Related to the Consumption and Handling of Game Meat in North America

Emerging foodborne pathogens present a threat to public health. It is now recognized that several foodborne pathogens originate from wildlife as demonstrated by recent global disease outbreaks. Zoonotic spillover events are closely related to the ubiquity of parasitic, bacterial, and viral pathogens present within human and animal populations and their surrounding environment. Foodborne diseases have economic and international trade impacts, incentivizing effective wildlife disease management. In North America, there are no food safety standards for handling and consumption of free-ranging game meat. Game meat consumption continues to rise in North America; however, this growing practice could place recreational hunters and game meat consumers at increased risk of foodborne diseases. Recreational hunters should follow effective game meat food hygiene practices from harvest to storage and consumption. Here, we provide a synthesis review that evaluates the ecological and epidemiological drivers of foodborne disease risk in North American hunter populations that are associated with the harvest and consumption of terrestrial mammal game meat. We anticipate this work could serve as a foundation of preventive measures that mitigate foodborne disease transmission between free-ranging mammalian and human populations.

Application of next generation sequencing for detection of protozoan pathogens in shellfish

Food and waterborne protozoan pathogens can cause serious disease in people. Three common species Cryptosporidium parvum, Giardia enterica and Toxoplasma gondii can contaminate diverse shellfish species, including commercial oysters. Current methods of protozoan detection in shellfish are not standardized, and few are able to simultaneously identify multiple species. Here, we present a novel metabarcoding assay targeting the 18S rRNA gene followed by next generation sequencing (NGS) for simultaneous detection of Cryptosporidium spp., Giardia spp. and T. gondii spiked into oyster samples. We further developed a bioinformatic pipeline to process and analyze 18S rRNA data for protozoa classification. The ability of the NGS assay to detect protozoa was later compared with conventional PCR. Results demonstrated that background amplification of oyster and other eukaryotic DNA competed with that of protozoa for obtained sequence reads. Sequences of target protozoans were obtained across all spiking levels; however, low numbers of target sequences in negative controls imply that a threshold for true positives must be defined for assay interpretation. While this study focused on three target parasites, the ability of this approach to detect numerous known and potentially unknown protozoan pathogens make it a promising screening tool for monitoring protozoan contamination in food and water.